Contact-stud and fixing for use with surface-contact systems of electric traction.



PATENTE!) SEPT. 29, 1903. v

, B. H. BDELL.; ooNTAcTsT'UD AND I IXING PoR USB wrm SURPAGE connorSYSTEMS v 0F ELETRIC TRTIN.

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CONTACT STUD AND FIXING Pon Usl-:- WITH SURPACECCNTACT 'SYSTEMS CBELECTRIC TRACTICN. APPLIOATIOR IILBDQIAY 13'. 1903.

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UNITED STATES :Patent-.ed september a9, 190e.Y

PATENT OFFICE.

BENJAMIN HARRY EEDELL, OE LONDON, ENGLAND, AssIeNOE OE ONE HALE ToWILLIAM eEIrEITHs, OE LONDON COUNTY, ENGLAND.

CONTACT-STUD AND FlXlNG FOR USE WITH SURFACE-CONTACT SYSTEMS 0F ELECTRICTRACTION.

SPECIFICATION forming part of Letters Patent No. 7 $9,816, datedSeptember 29, 1903.

Application tiled May 12, 1903.

To all whom it may concern.-

Be it known that I, BENJAMIN HARRY BE- DELL, engineer, of Nos. 41 and 42Hamilton House, Bishopsgate Street Without, in the county of London,England, have invented an Improved Contact-Stud and Fixing for Use withSurface-Contact Systems of Electric Traction; and I do hereby declarethe following Vto be a full,4 clear, and 'exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

This invention relates to an improved construction of combined road-studand magnetically-controlled switch-piece-and the method of bedding andiixing the saine for use in systems of electric traction in which aninclosed underground conductor supplying electrical energy istemporarily brought into electrical connection with the car travelingalong the ground above it by means of a magnet carried by the car,current passing to the car through the above-mentioned switch -piece androad-stud. I

One of the objects of the improvement is to increase the rapidity andthe certainty of the movement of the switch-piece, which is sovconstructed and'arranged thatit embodies a magnetic blow-out across' theswitch-con tacts and precludes adhesion by resid ual magnetism.

-Another is to provide simplicity in the construction of the ground xingand durability against wear by traffic. n

The accompanying drawings show a form of construction which embodies theabovementioned advantages.

Figure 1 is a vertical section through the axis of the stud, taken in adirection transverse to the line of the rails; and Fig. 2 is alongitudinal section.

These figures show the stud as composed of a stalk a, pivotallyconnected to astud-head l) by an eyebolt 0,' permitting the surface of bto be laid flush with the groundfsurface even when the stalk is notiixed perpendicularly thereto. The separate construction of the twoparts has the further advantage that the stud-head can be Vrf f newedwhen Worn without requiring the removal ofy the relatively more costlystalk and switch which Serial No. 156.321. (No model.)

' does not deteriorate. .The stalk o is composed of a number oflaminated plates of iron or steel which are partially insulated fromeach other and rigidly united by the rivets d d. A number of the platesin the middle portion are cut short at the upper end-to receive the eyeof the eyebolt c, which latter is connected to the other plates of thestalk by the pin e, Vthe ends of the plates being cut to a circularprofile and making close contact with the stud-head. At the lower endalso about one-half of the middle plates are out short, whereby thestalk is made fork-shaped. The two sides f f of the fork are spread alittle, and brass plates g g are inserted and secured by rivets each toits adjacent portion of the fork. In the space Within the fork aswitchpiece h is'suspended by aspring k. The switchlpiece' h also isformed of laminated steel or iron plates, which, with insulatingmaterial inserted between them, are rigidly united by rivets. Two stripsof copper m mare bound around the edges of the switch-piece and fastenedby serews. A slotwayn is formed in the plates which compose theswitch-piece, and through it is passed a brass pin o. The reduced vendsof the pin o are inserted through holes formed 'in the plates of thefork and riveted over. The enlarged'central portion of the pin forms aVdistance-piece between the two sides of the fork and partiallycontrolsand guides the movement ot the switch-piece. -The spring is attached tothe switch-piece by means of a piece of insulating material p, a few ofthe middle plates of h being cut short for the insertion of 10. Theupper end of the spring k is attached to `one or more of the centralplates of the stalk a, which are left a little longer than the othersfor the purpose and which have a hole bored in them. Permanentelectrical connection between theswitchniece h and the stalk a isestablished by fastening to each the ends of the flexible conductors qq.The insulating material p will preclude the conveyance of the electriceurrent through the, spring k. f

The strength of the spring lo' is so adjusted that it is just ableto'support the weight of the switch-piece in its highest position whenno car-magnet is over the stud.

c The stalk, with its suspended switch-piece,

is inserted in a stoneware pipe lr, which forms a vertical branch of aclosed horizontal stoneware conduit s, which ycontains the cable t,which is the medium for the conveyance of the electrical energy from thesource, to be picked up by the traveling car through successivestud-contacts. In the example shown the cable is bare and is made ofiron or steel wires. At points immediately beneath each of the studs thecable is supported in the conduit s by resting on a roller u, madeofinsulating material, which is mounted on a metal pin v, carried by theconduit. The'ppin i; protudes from the conduit at one end through awater-tight joint into the earth. The ends of these pins are joinedtogether and to the rails` at intervals by strips of metal.

The surfaces of the insulating-rollers have very undulating profiles forthe purpose of exaggerating the length of the path of leakage ofelectricity over the surface. Any which may leak that way will beintercepted by the pin fu and conveyed to the rail, and thus effectuallyshield the studs from becoming charged by leakage along the internalsurface of the conduit. Under these circumstances a stud can becomecharged only when it is beneath a car and under its protection.

At the constriction w in the stoneware pipe r packing is driven in andthe space above filled up with melted bitumen or the like Inaterial. Thesimple form of the stud-head shown will enable two granite blocks a: a:to be cut with facility to a shape adapted to lit together and surroundand support the studhead, thereby providing greater durability underheavy traffic than would be obtainable by any composition stone. Thismethod of fixing is adapted to allow the stud to be readily withdrawnforinspection and repair after the exposed upper surface has been heateda little to soften the bitumen.

The movement of the switch-piece h toward the iron cable t, which isrequisite to establish the required electric circuit, is due to themagnetic induction in the stud-head and stalk induced by the magnetcarried bythe car and transmitted to the iron of which the cable iscomposed. The circuit of the induced magnetism, which commences at thepole of the magnet just above the stud, passes through the stud-headdownward along the stalk a through the switch-piece h across the air-gapto lthe cable and is completed in a very distributed manner from thecable through conduit, earth, and air to the other pole of the magnet inthe car. The diminution of the air-gap between the switch-piece h andthe cable t will increase the conductance of the circuit or diminish itsmagnetic reluctance,

and in consequence the switch-piece will be attracted toward the cable.The downward movement of the switch-piece h will be at first scarcelyresisted by the spring c as it just balances its weight, by theextension, the upward pull of the spring will increase, but also, at amore rapid rate, will the downward attractive force. When' the excitingcause is removed by the onward movement of the car and its magnet, theinduced magnetism will die out and permit the spring, now at its maximumtensile force, to detach the switch-piece and raise it while there isstill sufficient magnetic induction across the contacts to produce ablowing-out effect on sparks, which otherwise would be liable to occur.

The copper strips m m prevent the contact of iron with iron andfacilitate detachment.

At high speeds the time available for the excitation of the magneticinduction is small. For this reason the magnetic lag due to eddycurrentsis reduced as much as possible by forming the stalk and switch-piece oflaminated plates.

The construction herein shown and described, in which the conductor ofthe electric energy is a bare cable of iron or steel wire mounted oninsulating-rollers and inclosed within a stoneware conduit, will givegreat facility for the insertion and removal of the conducting-cable forexamination, repair, or renewal. It will also permit the cable to bemoved a small distance after an interval of use and bring a freshportion immediately below a stud at the same time a new or clean portionof the surface of the insulating-roller will be brought into contactwith the cable.

With a cable mounted in a conduit according to this system it will beeasy to provide a remedy against the event of leakage of water into theconduit by an accident by constructing at intervals a number of chambersinto which such water may drain away from the conduit, facility beingalso provided for emptying those chambers.

Iplaiml. For use in a system of electric traction, by which electricalenergy is received by a car from a conductor contained in a closedconduit, placed underneath the track,through the medium of a successionof studs fixed in the ground, a stud, composed of magnetic material,having electrically connected therewith a switch-piece also composed ofmagnetic materialsuspended at the lower end of the stud, and anunderlying mass of magnetic material in electric connection with asource of electricity, the switch-piece being so suspended, relativelyto the stud and underlying mass, as, under magnetic induction, toapproach and make contact with the latter, and to be withdrawn whenmagnetic induction ceases.

2. A stud composed of magnetic material formed in two parts, pivotallyconnected forming a T-piece having, electrically connected therewith, aswitch-piece, also composed of magnetic material, suspended at the lowerend of the stud.

3. A stud composed of magnetic material formed in two parts, pivotallyconnected forming a T-piece, the stalk of which consists of laminatedplates having, electrically con- IIO nected therewith, a switch-piece,also composed of magnetic material, suspended at the lower end of thestud.

4. A stud composed of magnetic material having a head and a verticalstalk, the lower end of which is hollowed and contains, suspended by aspring within the hollow, `a switch-piece composed of magnetic material.

5. A stud composed of magnetic material, having a head and averticalstalk, the lower end of which is forkedV and contains, suspended by aspring within the fork, a switchpieoe electrically connected with thestud in an elastic manner, the switch-piece having a slotway, and thefork carrying a pin inserted through the slotway, substantiallyasdescribed.

6. A stud composed of magnetic material having, electrically connectedtherewith, a

y131cmAMIN HARRY BEDELL.

Witnesses:

J oHN ALFRED DoNNIsoN, WILLEAM HOLMES.

